We propose to study the interaction between the olfactory sensory neurons and the neuronal populations of the olfactory bulbar and cerebellar cortexes, by means of transplantation techniques. The two cortexes will be transplanted close to the intracranial side of the lamina cribrosa, to study their interaction with the olfactory sensory axons when the olfactory neurons are left in situ. Subsequently, the olfactory neurons (contained in fragments of olfactory mucosa), will be transplanted directly into the olfactory bulb and cerebellum of neonatal and adult rats to study their interaction with these cortexes when the latter are left in situ. In the third experiment both the olfactory neurons and the cortexes will be transplanted in the anterior chamber of the eye to study their interaction when both tissues are removed from their normal locations. Prelimininary studies have demonstrated that, when the olfactory neurons are transplanted away from the nasal cavity, they migrate away from the neuroepithelium and into the host's tissue. The destiny and the possible innteraction of the migrating olfactory neurons with the host's C.N.S. will be investigated. The proposed study will use histological techniques as well as ultrastructural, autoradiographic and immunohistochemical methods. The program proposes to define the inductive capacity of the olfactory neurons in a variety of experimental setting and to investigate their plasticity and migratory potential.